The present disclosure relates to a disk cartridge including an inner rotor that is rotatably supported inside a cartridge case and a shutter mechanism for opening and closing an opening formed in the cartridge case in accordance with a rotation of the inner rotor.
In recent years, a disk cartridge that rotatably accommodates a disk-like recording medium such as an optical disc, a magneto optical disc, and a magnetic disc is widely used. In general, a disk cartridge is capable of recording and/or reproducing information signals including music signals, video signals, and programs. As such a disk-like recording medium capable of recording information signals, there are known, for example, a writable write-once disc and a rewritable disc with which rewrite is possible.
For example, Patent Document 1 discloses a disk cartridge including a cartridge casing formed by superimposing a pair of shells, an inner rotor that forms a disk housing chamber inside the cartridge casing, an optical disc rotatably housed in the disk housing chamber, and a pair of shutter members for opening and closing an opening part provided to the cartridge casing in accordance with a rotation of the inner rotor.
In the conventional disk cartridge described above, the pair of shutter members include shaft portions that fit in support holes formed on a planar portion of the inner rotor. By fitting those shaft portions in the support holes, rotations about respective rotary shafts can be made. Moreover, the opening part of the cartridge casing is closed by the pair of shutter members being rotated in a direction in which they are brought close to each other, and the opening part is opened by the pair of shutter members being rotated in a direction in which they are set apart.
Patent Document 1: Japanese Patent Application Laid-open No. 2001-332057
However, in the conventional disk cartridge described above, when receiving a drop impact, for example, there is a fear that the shaft portions of the shutter members may come out of the support holes of the inner rotor. When an engagement operation between the inner rotor and the shutter members cannot be maintained as described above, it becomes impossible to perform desired rotation control on the shutter members, with the result that the disk cartridge becomes unusable.
On the other hand, there is a method of heat-caulking a tip end of the shaft portions of the shutter members fit in the support holes of the inner rotor for securing the engagement between the inner rotor and the shutter members. Since the tip end of the shaft portions is formed with an eave portion for preventing the shaft portions from being detached from the support holes due to the heat caulking, an engagement strength between the inner rotor and the shutter members can be enhanced.
However, the eave portion formed at the tip end of the shaft portions due to the heat caulking can hardly be said as having a sufficient strength, and, depending on a size of the impact to the disk cartridge, the eave portion may be damaged and the shutter members may thus be detached from the inner rotor. In this case, reliability of the disk cartridge is largely impaired.
Therefore, it is desired to provide a disk cartridge having high durability with respect to a drop impact.